NASA'S MARS PROBE STARTS DIGGING AGAIN AFTER MONTHS STUCK IN THE MUD

The space agency said it has used its robotic arm to help its heat probe, known as ‘the mole’, dig nearly 2cm over the past week. Designed to dig as much as 5m underground to gauge the heat escaping from the planet’s interior, the mole has only managed to partially bury itself since it started hammering in February 2019.

Scientists had hoped there would be a limited number of rocks below ground to impede the digging instrument as there are few rocks on the surface near the lander.

But they were forced to abandon the plan just two days after the initial dig as scientists said rocks were blocking the probe’s instruments.

The recent movement is the result of a new strategy, arrived at after extensive testing on Earth, which found that unexpectedly strong soil is holding up the mole’s progress.

The mole needs friction from surrounding soil in order to move, without it recoil from its self-hammering action will cause it to simply bounce in place. Pressing the scoop on InSight’s robotic arm against the mole, a new technique called ‘pinning’ appears to provide the probe with the friction it needs to continue digging.

Since 8 October the mole has hammered 220 times over three separate occasions. Images sent down from the spacecraft’s cameras have shown the mole gradually progressing into the ground. It will take more time – and hammering – for the team to see how far the mole can go.

“We’re rooting for our mole to keep going,” said the experiment’s lead scientist, Tilman Spohn of the German Aerospace Centre.

“When we first encountered this problem, it was crushing,” said the Jet Propulsion Laboratory’s Troy Hudson, who is leading the recovery effort.

“But I thought, ‘Maybe there’s a chance; let’s keep pressing on.’ And right now, I’m feeling giddy,” he said.

In April InSight recorded what is believed to be the first ‘Marsquake’, which demonstrates some plate activity underneath the surface.